1. Field of the Invention
The present invention relates to a method and apparatus for balancing thermal variations across a set of computer systems within a datacenter.
2. Related Art
Large businesses often maintain datacenters containing dozens or even hundreds of servers that provide various computational services. Because excessive heat can cause premature failure of components within servers, providing sufficient cooling to remove the heat generated by these servers is a primary concern for operators of these datacenters.
Hence, a major challenge for datacenter operators is to balance the temperature across a datacenter. Large disparities between “hot” and “cold” zones within a datacenter can result in cooling inefficiencies, which can significantly increase datacenter electricity costs. Furthermore, local “hot spots,” caused by an aggregation of computer systems or racks, can lead to poor long-term reliability of the computer systems located within the local hot spot.
Load scheduling techniques, which are designed to attain maximum job throughput for a given set of computing resources, can cause temperature imbalances across a datacenter. When the computer systems within the datacenter are operating at close to 100% of capacity, a typical load scheduler can enhance the throughput for all user workloads. However, when the computer systems are not operating near full capacity (which is the typical case) the load scheduler can naively dispatch jobs to any free computer system. This is undesirable because thermal imbalances can arise if the load scheduler directs loads to computer systems in racks that may already be operating at high temperatures, while computer systems in cooler racks remain underutilized. Furthermore, submitting new jobs to computer systems that are already operating at high temperatures is undesirable because it further accelerates temperature-related aging.
Hence, what is needed is a method and an apparatus for balancing thermal variations across a set of computer systems in a datacenter without the problems described above.